A chemical process is already known (see German patent no. 21 53 954) according to which rock can be chemically cut or its surface can be chemically processed. According to this process hydrogen and fluorine are supplied to a burner of the type of a Daniel cock. The developing hydrogen fluoride has a temperature of about 4000.degree. C. and splits up the present silicon-oxygen linkage and aluminum-oxygen linkage of the rock so that a clean cut is developed. However, this process to convert all the components of rock into gaseous fluorides and H.sub.2 O vapor with hydrogen fluoride has nothing to do with a process according to which solid reaction products are blown away, as is the case, for instance, processing rock with an oxygen lance.
Furthermore, it is mentioned in the above-cited patent that the developing hydrogen fluoride is toxic and is blown into the atmosphere according to the principle of a vacuum cleaner. Moreover, the possibility is mentioned to use the hydrogen fluoride flame under water which, however, has the result of the formation of very toxic hydrofluoric acid.